Electric switch



Jan. 29, 1929. 1,700,268

G. N. LEMMON ELECTRIC SWITCH Filed June 27, 1925 Fig. 1 7

7 a? N LEMMO/V.

Paamea Jan. 29, 1929.

GEORGE N. LEMMON, or BIRMINGHAM, ALABAMA.

ELECTRIC swrrcn.

Application filed June 27, 1925. Serial No. 40,065.

My invention relates to electric switches, and more particularly to airbreak switches for use upon high potential circuits.

The object of my invention is to provide an air. break switch havingample clearance for proper operation at high voltage and which afibrdssuflicient pressure between jaws and switch blade to give ample currentcarrying capacity while at the same time being operable to open andclose it without imposing objectionable strains upon the porcelain in-'sulators, one of which is movable to actuatethe switch. a

My invention contemplates operating the switch by means'which willimpart a double motion to the blade, on motion being arcual to providethe wide clearance between con tact parts when the switch is swung toopened or closed position and the other being a short motionlongitudinal of the switch blade which is effective during a part of theblade stroke and which is powerfully executed by reason of the availablehigh leverage, to force the blade into or to withdraw it from the switchjaws.

My invention further contemplates the modification of the operatingmechanism to swing the blade arcually either horizontally or verticallyas may be desired.

vMy invention further comprises'the novel details of'construction andarrangements of parts, which in their preferred embodiment only areillustrated in the accompanying drawings which form a part of thisspecification, and in which Fig. 1 is a side view of a horizontal throwswitch with the blade shown aboutto enter the jaws with a longitudinalmovement. Fig. 2 is a plan view showing the position of the bladerelative to its actuating means during its arcuate motion. 7

Fig. 3 is a plan view showing the blade at the com letion of the arcualmotion and just before t e commencement of the powerful drive whichimparts to the blade its short longitudinal motion which forces it intothe 1 switch jaws.

Fig. 4 is a plan view showing the switch blade thrust into closedposition between the aws.

Similar reference numerals refer to similar parts throughout thedrawings.

Referring to the embodiment of my invention shown in Figs. 1 to 4, Ishow the mechanism mounted upon a suitable base 1 carrying standard hightension current insulators 2 and 3, the insulator 3 being arranged forrotation about the pivotal bearing 4. The crank arm 5 ofl'ers a meansfor rotating the insulator 3 and for operating the switch either singlyor in combination with a group of similar units. proper comprises alongrigid blade 6 which co-acts with the switch jaws 7 mounted upon aninsulator 2, the switch blade itself being pivotally mounted on a pin 8disposed at the top of the insulator 3,near its center. -The blade isdisposed between'two fixed stops 9 and 10 on the insulator 3 and is freeto have a limited swinging movement between these stops. A spring 11,attached directly to the switch blade on the side adjacent to the stop10, normally engages said stop and provides a means for keeping theswitch blade, when free of contact with the jaws, in position againstthe stop 9. The jaws 7 have the usual flaring edges to receive and guidethe switch blade into position between them and in ad dition thereto oneof the jaws is provided with a stop 13 against which the blade willstrike so that it cannot swing through'the outer or. free ends of thejaws. The jaws of the switch, as viewed in plan, are cut away diagonallyand the enlarged end 12 of the Switchblade also has-its edgecorresponding- 1y bevelled so that when the switch blade completes itsfree arcual swing its end will lie between and parallel with thediagonal edges of the jaws. as is seen more clearly in Fig. 3. l

In operation, when the switch is. open the switch blade assumes theposition shown in :Fig. 2 and is held against the stop 9. As the crank 5is swung around, it rotates the insulator 3 and imparts an arcuatestroke to the blade, causing the latter to swing freely towards and toengage between the ends of the jaws 7, as shown in Fig. .3. Thereupon'the arcuate stroke of the switch blade is completed and the furtherrotation of the insulator will act to compress the spring. 11

and permit the blade to swing over against the stop 10. In thus swingingthe pivot point moves through an are which will act to impart a shortpowerful longitudinal motion to the switch blade that results inthrusting- -its end 12 deeply and firmly between the jaws 7; i. e., fromthe position shown in Fig. 3 to that shown in Fig. 4, and this completesthe closing of the switch. In reversing the movement of parts to openthe switch, the initial movement imparted'by the crank to The' switchmechanism position.

Though I have described with great particularity the details of theembodiment of .the invention herein shown, it is not to be construedthat I am limited thereto, as changes in arrangement and substitution ofe ui'valents may be made by those skilled in t e art without departingfrom the invention as defined in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. In an electric switch, a stationary assembled insulator carrying astationary contact member, a bodily movable assembled insulator, aloosely pivoted switch arm carried by the movable insulator, means tolimit the swing of the pivoted arm on the movable )insulator, and meansto swing said movable insulator thereby to make or break the switchcontact with successive lineal and angular motions of the switch arm.

2. In. an electric switch, a stationary insulator carrying a stationarycontactmember, a bodily movable insulator having pivotally mountedthereon a movable contact member,

means carried by the movable insulator to limit its swing, and crankmeans to swing said movable insulator about an axis parallel with theaxis of the pivot connection of the contact member to operate theswitch.

3. An electric switch according to claim 2,

in which a spring means is provided to urge the pivoted switch elementtowards the stationary contact'member.

4. An electric switch according to claim 2, in which the movable contactmember is pivoted on the movable insulator substantially nearer to thelatters axis than is the point of power application to the crank means.

5. In an electric switch, a stationary insulator carrying a stationarycontact member, a bodily movable insulator having a rigid contact armpivotally mounted on the top thereof to swing in a plane at right anglesto the axis of the insulator, stop means to limit the swingof saidarmrelative to the movable insulator, spring means adapted to urge the armtowards said contact member, and a crank having the movable insulatormounted thereon with its axis eccentric toand parallel with the axis ofthe crank, whereby the movable insulator is swung bodily to cause theswitch arm thereon to have a component motion in making and breakingcontact with the stationary contact.

In testimony whereof I aflix my signature.

GEORGE N. LEMMON.

